Dynamic distribution of client devices in gateway cluster

Abstract

A system for facilitating the dynamic selection of a gateway at an access node is provided. During operation, the system can select primary and standby gateways for a client device coupling the access node from a list of gateways associated with a gateway cluster based on an identifier of the client device. The gateway cluster can include a plurality of gateways coupled to the access node. The system can then forward traffic from the client device to the primary gateway. If there is a change in a set of parameters associated with the gateway cluster, the system can receive a policy indicating a change of gateway for the client device. The set of parameters indicates performance associated with the plurality of gateways. The system can select a new primary gateway for the client device based on the policy and redirect traffic from the client device to the new primary gateway.

What is claimed is: 
     
         1 . A method comprising:
 selecting, by an access node, a first primary gateway and a first standby gateway for a client device coupling the access node from a list of gateways associated with a gateway cluster based on an identifier of the client device, wherein the gateway cluster includes a plurality of gateways coupled to the access node;   forwarding, by the access node, traffic from the client device to the first primary gateway;   in response to a change in a set of parameters associated with the gateway cluster, receiving, by the access node, a policy indicating a change of gateway for the client device, wherein the set of parameters indicates performance associated with the plurality of gateways;   selecting, by the access node, a second primary gateway for the client device based on the policy; and   redirecting, by the access node, traffic from the client device from the first primary gateway to the second primary gateway.   
     
     
         2 . The method of  claim 1 , wherein the set of parameters indicates includes one or more of: traffic load of a gateway, number of client devices served by the gateway, processing response time for the traffic, and processor utility levels of the gateway. 
     
     
         3 . The method of  claim 2 , wherein the policy is generated in response to a parameter of the set of parameters reaching a threshold. 
     
     
         4 . The method of  claim 1 , wherein the access node is one of: an access switch and a wireless access point (AP), and the AP wirelessly couple the client device. 
     
     
         5 . The method of  claim 1 , wherein the list of gateways is indicated in a bucket map published by a leader gateway of the gateway cluster;
 wherein selecting the first primary gateway further comprises:
 applying a binary logical operation to the identifier to determine an index; and 
 determining that the first primary gateway corresponds to the index in the bucket map. 
   
     
     
         6 . The method of  claim 1 , further comprising forwarding, by the access node, data traffic to the second primary gateway while forwarding control traffic to the first primary gateway. 
     
     
         7 . The method of  claim 1 , wherein the list of gateways is indicated in a second policy published by a policy system, and wherein the list of gateways includes a subset of gateways of the gateway cluster selected by the second policy for control operations. 
     
     
         8 . The method of  claim 1 , further comprising receiving, by the access node, a third policy indicating a subset of gateways of the gateway cluster, wherein the subset of gateways is allowed to be selected for the client device, and wherein the second primary gateway is selected based further on the third policy. 
     
     
         9 . The method of  claim 1 , further comprising applying, by the access node, a selection mechanism to a subset of gateways of the gateway cluster to determine the second primary gateway, wherein the selection mechanism is based on one of:
 a hash function applicable to the identifier of the client device; and   a priority value associated with a respective gateway of the subset of gateways.   
     
     
         10 . The method of  claim 9 , wherein the subset of gateways is indicated in the policy in association with one or more of:
 the identifier of the client device;   a set of identifiers that includes the identifier of the client device;   a service set identifier (SSID) associated with the access node;   a subnetwork associated with the client device; and   a capability of the subset of gateways.   
     
     
         11 . A non-transitory computer-readable storage medium storing instructions that when executed by a processor of an access node of a network cause the processor to perform a method, the method comprising:
 selecting a first primary gateway and a first standby gateway for a client device coupling the access node from a list of gateways associated with a gateway cluster based on an identifier of the client device, wherein the gateway cluster includes a plurality of gateways coupled to the access node;   forwarding traffic from the client device to the first primary gateway;   in response to a change in a set of parameters associated with the gateway cluster, receiving a policy indicating a change of gateway for the client device, wherein the set of parameters indicates performance associated with the plurality of gateways;   selecting a second primary gateway for the client device based on the policy; and   redirecting traffic from the client device from the first primary gateway to the second primary gateway.   
     
     
         12 . The non-transitory computer-readable storage medium of  claim 11 , wherein the set of parameters indicates includes one or more of: traffic load of a gateway, number of client devices served by the gateway, number of client devices served by the gateway, and processor utility levels of the gateway, and wherein the policy is generated in response to a parameter of the set of parameters reaching a threshold. 
     
     
         13 . The non-transitory computer-readable storage medium of  claim 11 , wherein the access node is one of: an access switch and a wireless access point (AP), and the AP wirelessly couple the client device. 
     
     
         14 . The non-transitory computer-readable storage medium of  claim 11 , wherein the list of gateways is indicated in a bucket map published by a leader gateway of the gateway cluster;
 wherein selecting the first primary gateway further comprises:
 applying a binary logical operation to the identifier to determine an index; and 
 determining that the first primary gateway corresponds to the index in the bucket map. 
   
     
     
         15 . The non-transitory computer-readable storage medium of  claim 11 , wherein the method further comprises forwarding data traffic to the second primary gateway while forwarding control traffic to the first primary gateway. 
     
     
         16 . The non-transitory computer-readable storage medium of  claim 11 , wherein the list of gateways is indicated in a second policy published by a policy system, and wherein the list of gateways includes a subset of gateways of the gateway cluster selected by the second policy for control operations. 
     
     
         17 . The non-transitory computer-readable storage medium of  claim 11 , wherein the method further comprises receiving a third policy indicating a subset of gateways of the gateway cluster, wherein the subset of gateways is allowed to be selected for the client device, and wherein the second primary gateway is selected based further on the third policy. 
     
     
         18 . The non-transitory computer-readable storage medium of  claim 11 , wherein the method further comprises applying a selection mechanism to a subset of gateways indicated in the policy to determine the second primary gateway, wherein the selection mechanism is based on one of:
 a hash function applicable to the identifier of the client device; and   a priority value associated with a respective gateway of the subset of gateways.   
     
     
         19 . The non-transitory computer-readable storage medium of  claim 18 , wherein the subset of gateways is indicated in the policy in association with one or more of:
 the identifier of the client device;   a set of identifiers that includes the identifier of the client device;   a service set identifier (SSID) associated with the access node;   a subnetwork associated with the client device; and   a capability of the subset of gateways.   
     
     
         20 . A computer system, comprising:
 a processor;   a memory device; and   control circuitry to facilitate a selection logic block, a policy logic block, and a forwarding logic block;   wherein the selection logic block is to select a first primary gateway and a first standby gateway for a client device coupling the computer system from a list of gateways associated with a gateway cluster based on an identifier of the client device, wherein the gateway cluster includes a plurality of gateways coupled to the computer system;   wherein the forwarding logic block is to forward traffic from the client device to the first primary gateway;   wherein the policy logic block is to, in response to a change in a set of parameters associated with the gateway cluster, receive a policy indicating a change of gateway for the client device, wherein the set of parameters indicates performance associated with the plurality of gateways;   wherein the selection logic block is further to select a second primary gateway for the client device based on the policy; and   wherein the forwarding logic block is further to redirect traffic from the client device from the first primary gateway to the second primary gateway.